Denim fabric, either blue or black in color, is the basic material used to make jeans. Typically, blue denim is indigo dyed denim. As the denim fabric ages and is washed, it becomes softer and the color fades, with white areas becoming visible in the fabric. This texture and appearance is popular with consumers, and manufacturers of jeans have developed techniques to provide that texture and appearance to new Jeans. In one instance, manufacturers literally wash the Jeans in a washing machine with stones, such as pumice stones, to produce a stonewashed look. In another instance, manufacturers wash the jeans with cellulase enzyme, which also produces a stonewashed look. In that case, the enzyme acts on the cellulose in the jeans, releasing color, which produces light or white areas and lightens the blue or black color similar to stonewashing. Use of cellulase enzyme to stonewash Jeans is disclosed in U.S. Pat. Nos. 4,832,864 and 4,912,056 to Olson, and U.S. Pat. Nos. 5,006,126 and 5,122,159 to Olson et al, the entire disclosures of which are hereby incorporated herein by reference.
While stonewashed jeans are desirable, they cannot be economically made in a large array of colors. If denim is first dyed a specific color, other than blue or black, and then stonewashed, the process is very expensive due to the multiple steps and inventories of dyes and fabrics. If blue or black denim is first stonewashed and then merely dyed, the process is again very expensive due to multiple steps and inventories, and also, there is little contrast between the previously formed white areas and the rest of the fabric due to the effect of the dye, resulting in a dull appearance. Special expensive equipment is also necessary in these dying processes.
Thus, there is a continuing need to provide an improved denim fabric for use in making Jeans of varied colors.